Electroencephalographic activity during direct breastfeeding and breast milk expression in primiparous mothers.

Breastfeeding is recognized worldwide as the best option for infant feeding. Expressing breast milk is an alternative for mothers to provide their infants all the benefits of maternal milk. During breast milk expression, mothers receive a distinct kind of sensory stimulation, because there is no direct bodily or affective interaction with their infants, many women report feeling isolated, generating a love-hate relation with pumping, and even low levels of satisfaction while expressing breast milk. While it is well known that the prefrontal, parietal, and temporal cortices play important roles in the emotional and cognitive processing of maternal stimuli, knowledge about how these cortical areas function during breastfeeding is lacking. This study was designed to characterize EEG activity in the prefrontal and parietal cortices and the affective scores of primiparous breastfeeding mothers during two conditions of milk expression: breast milk expression and direct breastfeeding. Participants reported higher valence and arousal and a pleasant state during direct breastfeeding. In the direct breastfeeding condition, both prefrontal areas showed a higher absolute power (AP) of the slow bands, with a lower AP of the alpha band in the parietal cortex. A lower correlation between frontopolar and dorsolateral areas with a higher correlation between prefrontal and parietal cortices was obtained mainly in the right hemisphere. This EEG activity could be linked to an internal state of focused attention and, simultaneously, open monitoring of the environment that suggests an integration of the motive-emotional and cognitive processes necessary for adequate mother-baby interaction during direct breastfeeding.

Guía de laboratorio para el diagnóstico de pacientes con síndrome crioglobulinémico / Laboratory guidelines for the diagnosis of patients with cryoglobulinaemic syndrome

Los síndromes crioglobulinémicos comprenden un conjunto de manifestaciones que se encuentran en diversas enfermedades y que comparten un mismo mecanismo fisiopatológico: el depósito de crioglobulinas en lechos vasculares. La presencia de crioglobulinas es criterio diagnóstico de estos síndromes por lo que es imprescindible su correcta detección y caracterización. El Grupo de Inmunoquímica de la Sociedad Española de Inmunología ha realizado una revisión exhaustiva clínica y metodológica, debido a la heterogeneidad técnica interlaboratorios, con el objetivo de proporcionar una herramienta útil y efectiva para el diagnóstico de síndromes crioglobulinémicos

Cryoglobulinaemic syndromes include a collection of manifestations that are found in various diseases and that share a pathophysiological mechanism: cryoglobulin deposit in vascular beds. For these syndromes, the presence of cryoglobulins is a diagnostic criterion, and their correct detection and characterisation are therefore essential. The Immunochemistry Group of the Spanish Society of Immunology conducted a comprehensive clinical and methodological review, due to the interlaboratory heterogeneity in techniques, with the objective of providing a useful and effective tool for diagnosing cryoglobulinaemic syndromes

Laboratory guidelines for the diagnosis of patients with cryoglobulinaemic syndrome. / Guía de laboratorio para el diagnóstico de pacientes con síndrome crioglobulinémico.

Cryoglobulinaemic syndromes include a collection of manifestations that are found in various diseases and that share a pathophysiological mechanism: cryoglobulin deposit in vascular beds. For these syndromes, the presence of cryoglobulins is a diagnostic criterion, and their correct detection and characterisation are therefore essential. The Immunochemistry Group of the Spanish Society of Immunology conducted a comprehensive clinical and methodological review, due to the interlaboratory heterogeneity in techniques, with the objective of providing a useful and effective tool for diagnosing cryoglobulinaemic syndromes.

Support vector machines for explaining physiological stress response in Wood mice (Apodemus sylvaticus).

Physiological stress response is a crucial adaptive mechanism for prey species survival. This paper aims to identify the main environmental and/or individual factors better explaining the stress response in Wood mice, Apodemus sylvaticus. We analyzed alterations in fecal glucocorticoid metabolite (FCM) concentration - extensively used as an accurate measure of the physiological stress response - of wild mice fecal samples seasonally collected during three years. Then, support vector machines were built to predict said concentration according to different stressors. These statistical tools appear to be particularly suitable for small datasets with substantial number of dimensions, corroborating that the stress response is an extremely complex process in which multiple factors can simultaneously partake in a context-dependent manner, i.e., the role of each potential stressor varies in time depending on other stressors. However, air-humidity, temperature and body-weight allowed us to explain the FCM fluctuation in 98% of our samples. The relevance of air-humidity and temperature altering FCM level could be linked to the presence of an abundant vegetation cover and, therefore, to food availability and predation risk perception. Body-weight might be related to the stress produced by reproduction and other intraspecific relationships such as social dominance or territorial behavior.

Complement factor 5 (C5) p.A252T mutation is prevalent in, but not restricted to, sub-Saharan Africa: implications for the susceptibility to meningococcal disease.

Complement C5 deficiency (C5D) is a rare primary immunodeficiency associated with recurrent infections, particularly meningitis, by Neisseria species. To date, studies to elucidate the molecular basis of hereditary C5D have included fewer than 40 families, and most C5 mutations (13 of 17) have been found in single families. However, the recently described C5 p.A252T mutation is reported to be associated with approximately 7% of meningococcal disease cases in South Africa. This finding raises the question of whether the mutation may be prevalent in other parts of Africa or other continental regions. The aim of this study was to investigate the prevalence of C5 p.A252T in Africa and other regions and discuss the implications for prophylaxis against meningococcal disease. In total, 2710 samples from healthy donors within various populations worldwide were analysed by quantitative polymerase chain reaction (qPCR) assay to detect the C5 p.A252T mutation. Eleven samples were found to be heterozygous for p.A252T, and nine of these samples were from sub-Saharan African populations (allele frequency 0·94%). Interestingly, two other heterozygous samples were from individuals in populations outside Africa (Israel and Pakistan). These findings, together with data from genomic variation databases, indicate a 0·5-2% prevalence of the C5 p.A252T mutation in heterozygosity in sub-Saharan Africa. Therefore, this mutation may have a relevant role in meningococcal disease susceptibility in this geographical area.

Listening to a baby crying induces higher electroencephalographic synchronization among prefrontal, temporal and parietal cortices in adoptive mothers.

Women who adopt babies show caring behaviors and respond to stimuli from their infants just as biological mothers do, but several studies have shown that the cerebral functionality of biological mothers (BM) and adoptive mothers (AM) changes in relation to the type and emotional mean of the stimuli they receive from their babies. The complex perception and processing of different stimuli with emotional content (such as those emitted by babies) require functional synchronization among different cortical and subcortical brain areas. To determine whether the degree of functional synchronization between cortices varies when they perceive such stimuli, this study characterized the degree of cortical electroencephalographic (EEG) synchronization (correlation) among prefrontal, temporal and parietal areas in BM, AM and non-mothers while listening to a recording of a baby crying. BM showed a decreased EEG synchronization between the prefrontal and temporal cortices that may indicate a decrease in the modulatory control that the former exerts on the posterior cortices, and could be associated with deeper emotional involvement and increased sensitivity to the baby crying. The AM, in contrast, had higher degree of EEG synchronization between cortical areas in both hemispheres, likely associated with a greater modulation of the affective information of the crying baby, which allowed them to perceive it as less unpleasant. These data enrich our knowledge of the neurofunctional changes involved in motherhood, and of the neural processes that allow mothers (biological and adoptive) to be sensitive to their infants' cues and respond appropriately.

Observing videos of a baby crying or smiling induces similar, but not identical, electroencephalographic responses in biological and adoptive mothers.

It is well-known that adoptive mothers respond to cues from their babies in similar ways to biological mothers, and that cortical processing is critical for adequate motive-emotional maternal responses. This study used electroencephalographic activity (EEG) to characterize prefrontal, parietal and temporal functioning in biological mothers (BM), adoptive mothers (AM), and non-mothers (NM), while viewing videos of a baby smiling or crying. The BM presented higher absolute power (AP) in the delta and theta bands (associated with pleasant, positive emotional experiences) in the frontal and parietal areas under all conditions. In response to the smiling video, both types of mothers presented a lower AP in alpha1 in the three cortices (indicative of increased attention) and, mainly in temporal areas, a higher AP in the fast frequencies (beta and gamma, reflecting increased alertness to sensory stimuli and cognitive processing). This EEG pattern in the BM and AM could reflect the greater attention and, probably, the positive mood caused by the smiling video, showing that both are sensitive to these pleasant stimuli. When viewing the video of a baby crying, the AM had higher AP in the fast frequencies (temporal and parietal areas), indicating that they were more reactive to this unpleasant video, while the NM presented only a lower AP in alpha1 in all cortices, a finding that could be associated with the general activation induced by these unpleasant stimuli as a consequence of their lack of maternal experience. These findings should help improve our understanding of the neural mechanisms involved in the processing of sensorial stimuli that establish affective-emotional links during motherhood.

Enfermedad invasora por Neisseria meningitidis serogrupo 29E y deficiencia de C5 / Invasive disease due to Neisseria meningitidis serogroup 29E and C5 deficiency

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Long-term fish oil supplementation attenuates seizure activity in the amygdala induced by 3-mercaptopropionic acid in adult male rats.

Several studies have provided evidence of significant effects of omega-3 fatty acids on brain functionality, including seizures and disorders such as epilepsy. Fish oil (FO) is a marine product rich in unsaturated omega-3 fatty acids. Considering that the amygdala is one of the brain structures most sensitive to seizure generation, we aimed to evaluate the effect of long-term chronic FO supplementation (from embryonic conception to adulthood) on the severity of seizures and amygdaloid electroencephalographic activity (EEG) in a 3-mercaptopropionic acid (3-MPA)-induced seizure model using adult rats. Female Wistar rats were fed a commercial diet supplemented daily with FO (300mg/kg) from puberty through mating, gestation, delivery, and weaning of the pups. Only the male pups were then fed daily with a commercial diet supplemented with the same treatment as the dam up to the age of 150days postpartum, when they were bilaterally implanted in the amygdala to record behavior and EEG activity before, during, and after seizures induced by administering 3-MPA. Results were compared with those obtained from rats supplemented with palm oil (PO) and rats treated with a vehicle (CTRL). The male rats treated with FO showed longer latency to seizure onset, fewer convulsive episodes, and attenuated severity compared those in the PO and CTRL groups according to the Racine scale. Moreover, long-term FO supplementation was associated with a reduction of the absolute power (AP) of the fast frequencies (12-25Hz) in the amygdala during the seizure periods. These findings support the idea that chronic supplementation with omega-3 of marine origin may have antiseizure properties as other studies have suggested.

CubMemPC: Prueba Computarizada para Evaluar la Memoria a Corto Plazo Visoespacial con y sin Distractores / CubMemPC: Computarized Test to Assess the Visuospatial Short-Term Memory with and without Distractors

La memoria a corto plazo es un sistema que mantiene poca información durante segundos; se subdivide en memoria inmediata si sólo mantiene la información, y en memoria de trabajo, si además de mantener dicha información opera sobre ella de manera simultánea. Una prueba que se ha utilizado ampliamente para evaluar la memoria a corto plazo visoespacial es "los cubos de Corsi", la cual consiste en recordar secuencias crecientes de toques de cubos. En este artículo se presenta el funcionamiento y ventajas del programa CubMemPc, una versión computarizada de "los cubos de Corsi" diseñada para evaluar la memoria a corto plazo (inmediata y de trabajo) visoespacial. El programa permite la aplicación de distintas secuencias de "toques de cubos", el registro tanto de las secuencias efectuadas por los sujetos como su tiempo de ejecución e incluir estímulos visuales como distractores. Esto último permite el estudio del efecto de las emociones sobre la memoria a corto plazo. Dada su disponibilidad, flexibilidad y manejabilidad CubMemPc puede ser utilizado tanto por investigadores en el área de las neurociencias cognitivas, como por profesionales de la psicología en la evaluación de la memoria a corto plazo visoespacial con o sin distractores.

Short-term memory is a system that holds a small amount of information during seconds; it is subdivided into immediate memory, if the information is only stored temporarily and working memory, if the information is stored and manipulated simultaneously. "Corsi block task" is a test that has been widely used to assess visuospatial working memory; in this task the assessed subject must to remember increasing sequences of cubes touches. This article describes the operation and advantages of CubMemPc program, which is a computerized version of "Corsi block task" designed to assess visuospatial short-term memory (immediate and working memory). The program makes it possible the application of different sequences of "cube touches", the registration of both the subject's responses and execution time. Besides, it allows including visual stimuli as distracters, which permit to study the effects of emotion on short-term memory. Given its availability, flexibility and manageability CubMemPc can be used by researchers in the field of cognitive neuroscience and for psychology professionals in the assessment of visuospatial immediate memory and working memory with or without distracters.

Índices de calidad y eficiencia diagnóstica de varios marcadores de función renal para detectar la pérdida de parénquima en la edad pediátrica / Diagnostic efficiency and quality indexes of several markers of renal function for detecting the loss of parenchyma in paediatric patients

Introducción: En una muestra amplia de niños diagnosticados de malformaciones del tracto urinario y/o infección urinaria, hemos calculado los índices de calidad y eficiencia diagnóstica de cinco marcadores funcionales con la intención de comprobar cuáles son los más sensibles para detectar la existencia de una pérdida de parénquima renal. Pacientes y métodos: Estudio retrospectivo transversal en el que se han evaluado las historias clínicas de 179 pacientes en edad pediátrica (91 varones, 88 mujeres). En 102 de ellos (57%), la gammagrafía demostró pérdida de parénquima. Las lesiones morfológicas más frecuentes fueron las cicatrices renales. A todos se les había practicado, al menos, una prueba de concentración realizada con estímulo de desmopresina. Además, se recogieron los resultados de los cocientes albúmina/creatinina y N-acetilglucosaminidasa (NAG)/creatinina, el filtrado glomerular renal (FGR) y el volumen urinario. Resultados: Distribuidos los pacientes según la normalidad o anormalidad de la gammagrafía, se observaron diferencias estadísticamente significativas entre ambos (..) (AU)

Introduction: We analysed a large sample of children diagnosed with urinary tract malformations and/or infections and calculated diagnostic efficiency and quality indexes for five different functional markers, with the goal of testing which is the most sensitive for detecting a loss of renal parenchyma. Patients and method: Ours was a cross-sectional retrospective study in which the clinical histories of 179 paediatric patients (91 male and 88 female) were evaluated. In 102 of these patients (57%), a scintigraphy revealed loss of parenchyma. The most commonly observed morphological type of damage was renal scarring. All patients had undergone at least one desmopressin urine concentration test. We also analysed albumin/creatinine and N-acetyl-glucosaminidase (NAG)/creatinine ratios, glomerular filtration rate (GFR), and urine volume. Results: By distributing patients according to normal/abnormal scintigraphy, we observed statistically significant differences between the two groups in maximum urine osmolality and GFR. Urine volume was elevated in 31.3% of cases (sensitivity: 37.9%; specificity: 81.8%) and 24% had a defect in renal concentrating ability (sensitivity: 30.4%; specificity: 84.8%). Urinary albumin excretion was high in 12.2% of patients, and 7.2% had a high NAG/creatinine ratio. GFR was low in only 5.7% of patients. These last two markers were the least sensitive but most specific for detecting a loss of renal parenchyma (100%). Conclusions: In our study, the most sensitive functional tests for detecting the loss of renal parenchyma were the two that take into account the ability of the kidney to manage water, i.e. urine volume and maximum urine osmolality. These two tests had specificity >80%. However, the maximum specificity was obtained by the NAG/creatinine ratio and GFR, which were, conversely, the least sensitive tests. A normal GFR does not necessarily show normal renal function (AU)

Diagnostic efficiency and quality indexes of several markers of renal function for detecting the loss of parenchyma in paediatric patients.

INTRODUCTION: We analysed a large sample of children diagnosed with urinary tract malformations and/or infections and calculated diagnostic efficiency and quality indexes for five different functional markers, with the goal of testing which is the most sensitive for detecting a loss of renal parenchyma. PATIENTS AND METHOD: Ours was a cross-sectional retrospective study in which the clinical histories of 179 paediatric patients (91 male and 88 female) were evaluated. In 102 of these patients (57%), a scintigraphy revealed loss of parenchyma. The most commonly observed morphological type of damage was renal scarring. All patients had undergone at least one desmopressin urine concentration test. We also analysed albumin/creatinine and N-acetyl-glucosaminidase (NAG)/creatinine ratios, glomerular filtration rate (GFR), and urine volume. RESULTS: By distributing patients according to normal/abnormal scintigraphy, we observed statistically significant differences between the two groups in maximum urine osmolality and GFR. Urine volume was elevated in 31.3% of cases (sensitivity: 37.9%; specificity: 81.8%) and 24% had a defect in renal concentrating ability (sensitivity: 30.4%; specificity: 84.8%). Urinary albumin excretion was high in 12.2% of patients, and 7.2% had a high NAG/creatinine ratio. GFR was low in only 5.7% of patients. These last two markers were the least sensitive but most specific for detecting a loss of renal parenchyma (100%). CONCLUSIONS: In our study, the most sensitive functional tests for detecting the loss of renal parenchyma were the two that take into account the ability of the kidney to manage water, i.e. urine volume and maximum urine osmolality. These two tests had specificity >80%. However, the maximum specificity was obtained by the NAG/creatinine ratio and GFR, which were, conversely, the least sensitive tests. A normal GFR does not necessarily show normal renal function.

[Identification of components of metabolic syndrome in Mexican patients hospitalized for acute ischemic coronary syndrome: a tool for prevention]. / Identificación de componentes del síndrome metabólico en pacientes mexicanos hospitalizados por síndrome isquémico coronario agudo: una herramienta para la prevención.

OBJECTIVE: To determine the prevalence of metabolic syndrome (MS) and its risk factors in patients with Acute Ischemic Coronary Syndrome (AICS) in a tertiary hospital. METHODS: A total of 65 patients admitted to Cardiac Intensive Care Unit with myocardial infarction or unstable angina participated. MS was diagnosed in accordance to the Adult Treatment Panel III (ATPIII) criteria. RESULTS: The total prevalence of MS was 84.6% (95% CI: 75.6 to 93.6). MS was more frequent in women, persons with obesity according to the body mass index (BMI), family background diabetes, and dyslipidemia. Phenotype predictors of MS were: BMI (OR=2.12, 95% CI: 1.24, 3.17) and familiar history of dyslipidemia (OR=0.026, 95% CI: 0.003, 0.587). CONCLUSIONS: The prevalence of MS with AICS is higher than that reported in other populations. This fact is alarming if this risk is maintained in the Mexican population.

[Should a cystography be performed on all breastfeeding infants with mild to moderate dilatation of the urinary tract? Renal function tests can help to answer this question]. / ¿Debe realizarse una cistografía a todos los lactantes con dilatación leve y moderada de las vías urinarias? Las pruebas de función renal pueden ayudar a responder a esta pregunta.

INTRODUCTION: Pyelectasis can be defined as mild to moderate dilatation of the urinary tract and is diagnosed by means of an ultrasound scan (0.5-2cm transverse diameter in the initial ultrasound performed after birth). There is some disagreement about whether cystography should be indicated as standard practice. The aim of this study was to establish if renal function tests are useful in determining which cases of mild to moderate dilatation of the urinary tract do not require an initial cystography. PATIENTS AND METHODS: The study was conducted on 79 infants (57 males, 22 females) with pyelectasis. Seventy-three were diagnosed in utero and 6 after birth. All infants underwent at least one cystography and one desmopressin urine concentration test before one year of age. RESULTS: Compared to infants without vesicoureteral reflux (VUR) (n=68), infants with VUR (n=11; two with Grade I, three with Grade II, five with Grade III, two with Grade IV) showed a significantly lower (P=.006) maximum urine osmolality and a significantly higher microalbumin/creatinine ratio (P<.001) and NAG/creatinine ratio (P=.003). The negative predictive value of the first two tests was 93%. Sensitivity of the maximum urine osmolality to detect VUR was 72.7% (specificity 63.2%). Sensitivity of the microalbumin/creatinine ratio to detect VUR was 62.5% (specificity 75%). The positive probability ratio (PR) was 1.29 for the NAG/creatinine ratio, 2.03 for the maximum urine osmolality and 2.5 for the microalbumin/creatinine ratio. The negative PR was 0.95 for the NAG/creatinine ratio, 0.43 for the maximum urine osmolality and 0.5 for the microalbumin/creatinine ratio. CONCLUSIONS: Pyelectasis is a benign condition. Only 2 patients required pharmacological intervention (prophylactic treatment for VUR Grade IV patients). Initially at least, cystography should not be indicated in cases of microalbuminuria and/or normal urine concentrations.

Orchiectomy modifies the antidepressant-like response of nicotine in the forced swimming test.

Several studies have demonstrated that nicotine (NIC) exhibits antidepressant-like effects. In addition, it has been suggested that sexual hormones participate in the antidepressant actions of antidepressives. The present study was designed to analyze the effect of orchiectomy and the supplementation of testosterone propionate (TP) or 17ß-estradiol (E(2)) on the antidepressant properties of NIC using the forced swimming test (FST), as well as to determine possible changes in the FST during different time periods after orchiectomy. In order to evaluate the influences of orchiectomy on the effects of NIC, the study first evaluated the effects of different time periods on orchiectomized rats (15, 21, 30, 45 and 60 days) that were subjected to the FST. Then, different doses of NIC (0.2, 0.4, 0.8, 1.6 mg/kg, sc) were administered for 14 days to both intact and orchiectomized rats (after 21 day) which were then also subjected to the FST. Finally, the influence of the TP or E(2) supplementation on the antidepressant-like effect of NIC on orchiectomized rats (after 21 days) was also analyzed. Results reveal that orchiectomy significantly increased immobility behavior and decreased swimming and climbing up to 60 days after castration. In contrast, NIC decreased immobility behavior and increased swimming in intact rats; whereas orchiectomy suppressed this antidepressant effect of NIC. Only with E(2) supplementation was it possible to restore the sensitivity of the castrated rats to NIC. These results suggest that E(2) was able to facilitate the antidepressant response of NIC in orchiectomized rats.

Circadian activity of corticosterone in an animal model of depression: response to muscarinic cholinergic stimulation.

Neonatal treatment with clomipramine (CMI) in rats induces multiple behavioral alterations during adulthood that resemble certain symptoms of human depression, such as impairments of pleasure-seeking behaviors. CMI may also induce permanent changes in the reactivity of the hypothalamic-pituitary-adrenocortical axis (HPA) to different stimuli; however, the endocrinal changes induced by this treatment are still a matter of debate. In the present study, we evaluated the levels of corticosterone in rats treated in the neonatal period with CMI in basal conditions (0, 6, 12 and 18 h after lights on) and after treatment with the antidepressant fluoxetine (FLX; 5mg/kg for 14 days). To evaluate the response of the HPA axis to a cholinergic agonist, we analyzed the effect of oxotremorine administration (OXO; 0.4, 0.8 mg/kg) on plasma levels of corticosterone. Administration of OXO took place at the beginning of each one of the two phases of the light-dark cycle (time points 0 and 12h, respectively). Results showed an increase in basal plasma levels of corticosterone in CMI-treated rats at time point zero and at 6h after the onset of the light period. While treatment with FLX reversed the increase in corticosterone plasma levels in CMI-treated rats, the results regarding cholinergic stimulation indicate that those rats do not respond to the administration of a low dose of OXO (0.4 mg/kg) at the onset of the dark phase (time point 12h). In conclusion, this study supports the hypothesis that neonatal treatment with CMI induces a hypersecretion of corticosterone in adulthood that was reversed through treatment with the antidepressant FLX. The CMI-treated rats showed a hyporesponse to cholinergic stimulation with OXO at low doses and at the beginning of the dark phase. Thus, the present results do not support the assumption that an increased sensitivity of the muscarinic cholinergic system is one of the possible correlates of the behavioral alterations seen in CMI-treated rats.

HANOIPC3: a computer program to evaluate executive functions.

This article describes a computer program (HANOIPC3) based on the Tower of Hanoi game that, by analyzing a series of parameters during execution, allows a fast and accurate evaluation of data related to certain executive functions, especially planning, organizing and problem-solving. This computerized version has only one level of difficulty based on the use of 3 disks, but it stipulates an additional rule: only one disk may be moved at a time, and only to an adjacent peg (i.e., no peg can be skipped over). In the original version--without this stipulation--the minimum number of movements required to complete the task is 7, but under the conditions of this computerized version this increases to 26. HANOIPC3 has three important advantages: (1) it allows a researcher or clinician to modify the rules by adding or removing certain conditions, thus augmenting the utility and flexibility in test execution and the interpretation of results; (2) it allows to provide on-line feedback to subjects about their execution; and, (3) it creates a specific file to store the scores that correspond to the parameters obtained during trials. The parameters that can be measured include: latencies (time taken for each movement, measured in seconds), total test time, total number of movements, and the number of correct and incorrect movements. The efficacy and adaptability of this program has been confirmed.

Testosterone, androstenedione, and 5alpha-dihydrotestosterone on male sexual behavior and penile spines in the hamster.

The expression of masculine sexual behavior (MSB) in male hamsters is optimally stimulated by aromatizable androgens like androstenedione (AD) and testosterone (T), while the non-aromatizable androgen, 5alpha-dihydrotestosterone (DHT), exerting potent androgenic peripheral effects, only in high doses maintains MSB after castration. No data exist on the ability of these androgens to restore long intromissions after castration. In this study, AD, T, and DHT were administered to four-week gonadectomized, sexually experienced male hamsters, for three weeks, in doses of 25 microg/day or up to 1000 microg/day to compare their potency in restoring MSB, penile size, and penile spines growth. Plasma levels of these steroids and the metabolites estrone and estradiol, were determined at the end of the treatment period. Gonadectomy completely suppressed MSB and induced a regression of penile spines. AD was more potent than T in restoring MSB, ejaculatory behavior being displayed by most castrated subjects with a lower dose of AD (50 microg/day) than of T (300 microg/day), and long intromissions being shown by all AD-treated castrated hamsters but only by 20% of T-treated ones, when doses of 1000 microg/day were given. DHT did not stimulate any copulatory response. The three androgens, even at the lowest dose, partially stimulated penis and penile epithelium growth, DHT showing the highest potency. Treatment of castrated hamsters with AD (50 microg/day), restored steroid levels to similar values as those of intact animals. These results show that AD and T restored MSB even with a partial stimulation of penile spines growth, AD being more potent than T. In contrast, DHT did not restore MSB in the hamster in spite of its peripheral androgenic potency.

Different functionality of the medial and orbital prefrontal cortex during a sexually motivated task in rats.

This study was designed to analyze whether the electroencephalographic (EEG) activity of the medial (mPFC) and orbital prefrontal cortex (oPFC) was modified during the performance of male rats in a T maze under two different conditions, sexually motivated (with previous intromission and females in the goal boxes of the lateral arms) or sexually non-motivated (without previous intromission and with empty goal boxes). Relative power (RP) of three EEG band frequencies, and inter-hemispheric correlation (r) were calculated and a comparison was made between rats under motivated and non-motivated conditions. In the mPFC of sexually motivated males, an increase of the RP in the 6-7 Hz band as well as a decrease in the 8-11 Hz band was observed in relation to an awake-quiet state and during the walk in the maze stem. Similarly, an increase in the r of the 6-7 Hz band was observed during the walk in the maze stem and when remaining near to a receptive female, when compared to non-motivated males. In the oPFC, only the RP of the 6-7 Hz band was increased during the walk in the maze stem of the motivated males. These data suggest that, among sexually motivated males, the mPFC is involved both in anticipatory and motor execution during the performance of the T maze task, whereas the oPFC is only involved in the motor execution of the T maze. These results are in line with other studies suggesting that the mPFC and oPFC are functionally distinct, regions which may work together during certain behaviors and physiological conditions.